To the people who don't "believe" in alien life - please, listen to yourselves. There is nothing to believe here, it is simple mathematics. The universe is so massive that we can't even comprehend its size. There are as many galaxies and planets as there are individual grains of sand on every beach on Earth. So yes, chances are that another intelligent life form did evolve somewhere out there, possibly thousands or more different kinds.
Crossing the vast distances of space is another matter entirely. No one would ever be stupid enough to attempt an interstellar flight near the speed of light, given the complications that would arise from that. Obviously some sort of concept like folding space or wormholes etc would need to be used to get around that issue. We have been around for a few hundred thousand years and our space age has barely begun. Who knows what a few hundred/thousand years will bring, not that any of us here would be able to comprehend it.
Please also consider that any highly advanced life form capable of reaching Earth wouldn't have the slightest interest in a backwards species like us.